#pragma once
#include <iostream>
#include <string>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <unistd.h>
#include "Comm.hpp"

const int gdefaultid = -1;
const int gsize = 4096;
const std::string pathname = ".";
const int projid = 0x66;
const int gmode = 0666;

#define CREATER "creater"
#define USER "user"

class Shm
{
private:
    void CreatHelper(int flg)
    {
        printf("key: 0x%x\n", _key);
        // 共享内存的生命周期随内核
        _shmid = shmget(_key, _size, flg);
        if (_shmid < 0)
        {
            ERR_EXIT("_shmget");
        }
        printf("shmid: %d\n", _shmid);
    }
    void Creat()
    {
        CreatHelper(IPC_CREAT | IPC_EXCL | gmode);
    }
    void Get()
    {
        CreatHelper(IPC_CREAT);
    }
    void Attach()
    {
        _start_mem = shmat(_shmid, nullptr, 0);
        if ((long long)_start_mem < 0)
        {
            ERR_EXIT("shmat");
        }
        printf("shmat success\n");
    }
    void Detach()
    {
        int n = shmdt(_start_mem);
        if (n == 0)
        {
            printf("detach success\n");
        }
    }
    void Destory()
    {
        Detach();
        if (_usertype == CREATER)
        {
            int n = shmctl(_shmid, IPC_RMID, 0);
            if (n == 0)
            {
                printf("destory success\n");
            }
            else
            {
                ERR_EXIT("shmctl");
            }
        }
    }

public:
    Shm(const std::string &pathname, int projid, const std::string &usertype)
        : _shmid(gdefaultid),
          _size(gsize),
          _start_mem(nullptr),
          _usertype(usertype)
    {
        _key = ftok(pathname.c_str(), projid);
        if (_key < 0)
        {
            ERR_EXIT("ftok");
        }
        if (_usertype == CREATER)
        {
            Creat();
        }
        else if (_usertype == USER)
        {
            Get();
        }
        else
        {
        }
        Attach();
    }
    void *VirtualAddr()
    {
        printf("VirtualAddr: %p\n", _start_mem);
        return _start_mem;
    }
    int Size()
    {
        return _size;
    }
    void Attr()
    {
        struct shmid_ds ds;
        int n = shmctl(_shmid, IPC_STAT, &ds);
        printf("shm_segsz: %ld\n", ds.shm_segsz);
        printf("key: 0x%x\n", ds.shm_perm.__key);
    }
    ~Shm()
    {
        std::cout << _usertype << std::endl;
        if (_usertype == CREATER)
        {
            Destory();
        }
    }

private:
    int _shmid;
    key_t _key;
    int _size;
    void *_start_mem;
    std::string _usertype;
};
